In the prior art, an example of an edge flaw inspection device for searching for edge flaws such as cracks, chips or polishing flaws in narrow, long edges such as the peripheral edges of silicon wafers is described in Japanese Patent No. 2999712.
This device is provided with a rotating table that horizontally rotates a silicon wafer by suctioning the bottom of the silicon wafer at a location near its center. Light is irradiated onto the edge of the silicon wafer being horizontally rotated by this rotating table and the light reflected by the edge is detected and analyzed to detect the type of edge defect or surface roughness and so forth.
However, since the rotating table of this device suctions the bottom of a silicon wafer, inspections cannot be carried out after the top and bottom of the silicon wafer have been polished, thereby enabling inspections to only be carried out before the top and bottom of the silicon wafer are polished.
Since edge defects have a high potential to expand or occur due to stress generated during polishing of the tops and bottoms of silicon wafers, it is preferable to inspect for edge defects and so forth after polishing the top and bottom of silicon wafers.
In consideration of these circumstances, an object of the present invention is to provide a wafer rotating device that enables silicon wafers to be rotated without contacting the top and bottom of the silicon wafer, and an edge flaw inspection device provided with this wafer rotating device.